1. Field of the Invention
The present invention pertains to an electronic speed controller with modular layout comprising, in a cabinet, an inverter delivering polyphase electric current and provided with static switches operated by an electronic control/command assembly linked to a display and dialogue module serving for control, command and for visualization, disposed on the front face.
2. Discussion of the Background
An electronic speed controller such as that shown diagrammatically in FIG. 1 makes it possible to feed an adjustable polyphase current to an asynchronous motor in such a way as to vary its speed. It comprises an inverter with electronic power switches which is supplied, under a filtered DC voltage, via a rectifier. This inverter delivers regulated AC current on the phases of the motor.
The technique of controlling electronic power switches is known by the name Pulse Width Modulation (PWM for short), the aim being to generate a voltage which is as close as possible to a sinusoid.
A display and dialogue assembly usable by the operator is situated on the front face. It generally exhibits a screen or visualization components, control buttons and at least one communication connector enabling the controller to be made to communicate with other automation apparatus.
Document EP 0660 652 discloses a controller of the above type. The compactness of such a controller is not optimized and does not allow the simultaneous incorporation of several optional cards.